(MIDTERM) HH L5.1 Neurotransmitters

ACETYLCHOLINE (ACh)

Chemical structure significantly different from that of other neurotransmitters; active in CNS and in both somatic and autonomic parts of PNS; binds to ACh receptors (cholinergic receptors) in PNS to open ion channels in the postsynaptic membrane and stimulate muscle contraction

AMINO ACIDS

Molecules with both carboxyl (—COOH) and amine (—NH2) groups and various R groups; act as important transmitters in the CNS

Glutamate

AMINO ACID: __________

• Excites activity in neurons to promote cognitive function in the brain (learning and memory); most common neurotransmitter in the brain; opens Na+ channels

Gamma-aminobutyric acid (GABA)

AMINO ACID: __________

• Synthesized from glutamate; primary inhibitory neurotransmitter in the brain; also influences muscle tone; opens or closes various ion channels

Glycine

AMINO ACID: __________

• Inhibits activity between neurons in the CNS, including retina; opens Cl– channels

MONOAMINES

Molecules synthesized from an amino acid by removing the carboxyl group and retaining the single amine group; also called biogenic amines

Serotonin or 5-hydroxytryptamine (5-HT)

MONOAMINES: __________

• Has various functions in the brain related to sleep, appetite, cognition (learning, memory), and mood; modulates actions of other neurotransmitters

Catecholamines

MONOAMINES: __________

• A distinct group of monoamines

Dopamine

MONOAMINES: __________

• Produces inhibitory activity in the brain; important roles in cognition (learning, memory), motivation, behavior, and mood; opens K+ channels, closes Ca2+ channels

Norepinephrine (noradrenaline)

MONOAMINES: __________

• Neurotransmitter of PNS (sympathetic division of autonomic nervous system) and specific CNS regions

Epinephrine (adrenaline)

MONOAMINES: __________

• Has various effects in the CNS, especially the spinal cord, thalamus, and hypothalamus

NEUROPEPTIDES

Small polypeptides act as signals to assist in and modulate communication among neurons in the CNS

Enkephalin

NEUROPEPTIDES: __________

• Helps regulate response to noxious and potentially harmful stimuli

Neuropeptide Y

NEUROPEPTIDES: __________

• Involved in memory regulation and energy balance (increased food intake and decreased physical activity)

Somatostatin

NEUROPEPTIDES: __________

• Inhibits activities of neurons in specific brain areas

Substance P

NEUROPEPTIDES: __________

• Assists with pain information transmission into the brain

Cholecystokinin (CCK)

NEUROPEPTIDES: __________

• Stimulates neurons in the brain to help mediate satiation (fullness) and repress hunger

Beta-endorphin

NEUROPEPTIDES: __________

• Prevents release of pain signals from neurons and fosters a feeling of well-being

Neurotensin

NEUROPEPTIDES: __________

• Helps control and moderate the effects of dopamine

Adenosine

Also part of a nucleotide, inhibits activities in certain CNS neurons

Nitric oxide

Involved in learning and memory; relaxes muscle in the digestive tract; important for relaxation of smooth muscle in blood vessels (vasodilation)